<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
    <style>
      input:checked {
          width: 200px;
          height: 200px;
        border: 1px solid #f00;
      }
    </style>
  </head>
  <body>
    <input type="checkbox" checked="checked"  />
    <input type="checkbox" />
    <input type="checkbox" />
    <input type="checkbox" />
    <input type="checkbox" />
  </body>
</html>
